Abstract
QUESTION: I read last year that Canada has followed the United States in fortifying flour with folic acid to prevent neural tube defects. Do we know yet whether this strategy is working? ANSWER: In Canada, flour is fortified with folic acid to a level of 0.15 mg/100 g. Although a mandatory date was set for November 1, 1998, most if not all companies implemented the change on or before January 1, 1998. Recent figures from the United States, where the deadline for fortification was January 1998, show that by March 1999, mean folate levels in flour doubled, substantially decreasing the risk for neural tube defects.